This invention relates to a laminated wood flooring product, and a wood floor assembled from strips of the laminated wood flooring product. The flooring product which is the subject of this invention relates generally to products which are intended to simulated far more expensive solid wood flooring, such as oak, maple or ash. The desire to create a flooring product simulating solid wood flooring is apparent for reasons other than cost. For example, when a solid wood flooring panel is subjected to moisture, the width of the panel expands by as much as 11%. Because of this expansion, a stable solid wood floor can be difficult to maintain.
Width expansion and instability of wood is a result of the wood's hydroscopic nature. One way to stabilize an otherwise unstable wood product is to make it out of plywood. A piece of plywood is made by peeling a log to create thin wood strips. These strips are glued together and turned ninety degrees from the adjacent strips. This effectively stabilizes the unstable widthwise direction of the wood panel, thereby resulting in a more stable wood product.
In order to achieve a solid wood appearance without moisture expansion problems, a laminated wood flooring product was produced. This flooring product has a top, relatively thin veneer layer of oak, maple, ash or some other wood. The top layer is the exposed surface of the laminated wood floor when the floor is laid. When properly installed, the floor appears to be a solid wood floor, when in fact the floor is far less expensive than a solid wood floor. This lower cost is principally due to the use of less slow-growing hardwoods in favor of cheaper, faster-growing softwoods such as lauan or the like. Since laminated wood flooring products expand and contract in the presence of moisture by less than 2%, they provide a more stable floor.
Laminated wood floors are known in the art, but they are subject to a number of problems. For example, some laminated wood floors are specified as only being suitable for installation over certain types of subfloors. In other instances, subfloors must be removed because of poor condition, or because of irregularities in the surface which prevent proper installation. This is a particular problem since many older flooring materials contain asbestos, and are therefore expensive and potentially dangerous to remove. Prior art laminated wood floors are often subject to warping twisting and cupping, thereby requiring replacement or sanding to refurbish. In addition, a laminated wood floor which does not adhere to the subfloor at all points will create a hollow sound, and will flex slightly when walked on, clearly indicating that the floor is not a solid floor. Prior art laminated wood flooring strips are relatively stiff, thereby requiring a strong adhesive, such as a chlorinated solvent adhesive, to bond the floor to the subfloor. This is particularly true of subfloors which may have irregularities in the surface.
The chlorinated solvent adhesive used to bond the laminated wood flooring to the concrete had to be very rubbery, because despite the lamination, the flooring moved slightly through the years. This rubbery adhesive creates difficulties in installation. Furthermore, methyl chloroform is typically a principle ingredient in chlorinated solvent adhesives. Vapors emitted from this chemical are not only an environmental threat, but are also potentially damaging to household appliances, such as hot water heaters and furnaces. Regardless, even with a very strong adhesive, bowing, sideways sliding and similar problems are common.
In addition prior art laminated wood flooring strips have tongue and groove locking edges on both ends and side edges. This prevents pieces from being cut to length except on the periphery of the floor being laid. The presence of tongue and groove locking edges on the side edges and ends of the strips means that each flooring strip, as installed, must be shifted both sideways and endways to lock the tongue and groove locking members with the mating members of the end and side adjacent strips. The presence of tongue and groove locking edges o the side edges and ends of the strips also creates a problem known as "overwood," meaning that the respective surfaces of adjacent strips, when installed, are not exactly flush.
A prior attempt has been made to correct these problems. The Hartco "Pattern-Plus" laminated wood floor is a two-piece laminated floor, which has small wooden "slats" glued to the back side of the wooden flooring strips to create a "slatted" appearance, with small spaces between each flat to add additional flexibility to the floor, and to permit conformation to slight irregularities in the subfloor. This product has tongue and groove locking edges on both ends and side edges. As is apparent, gluing numerous small pieces of wood to the back of the flooring strips is a costly and time-consuming process.
The invention according to this application solves these problems in an inexpensive and efficient manner.